CVE-2026-11331

Name	CVE-2026-11331
Description	An attacker who knows (or guesses) that a resolver uses RPZ with wildcard CNAME policies can craft query names long enough to trigger a NAMETOOLONG error condition during RPZ processing. This is not handled correctly and may lead to defeating the RPZ rule. It also may lead to an unexpected exit of the BIND 9 software. This issue affects BIND 9 versions 9.16.0 through 9.18.50, 9.20.0 through 9.20.24, 9.21.0 through 9.21.23, 9.16.8-S1 through 9.18.50-S1, and 9.20.9-S1 through 9.20.24-S1.
Source	CVE (at NVD; CERT, ENISA, LWN, oss-sec, fulldisc, Debian ELTS, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
References	DSA-6395-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source Package	Release	Version	Status
bind9 (PTS)	bullseye	1:9.16.50-1~deb11u2	vulnerable
	bullseye (security)	1:9.16.50-1~deb11u5	vulnerable
	bookworm, bookworm (security)	1:9.18.49-1~deb12u1	vulnerable
	trixie	1:9.20.23-1~deb13u1	vulnerable
	trixie (security)	1:9.20.26-1~deb13u1	fixed
	forky, sid	1:9.20.24-1	vulnerable

The information below is based on the following data on fixed versions.

Package	Type	Release	Fixed Version	Urgency	Origin	Debian Bugs
bind9	source	trixie	1:9.20.26-1~deb13u1		DSA-6395-1
bind9	source	(unstable)	(unfixed)

https://kb.isc.org/docs/cve-2026-11331